摘要
      海拔高度对水生微生物组有很大影响。然而，我们对海拔升高对功能基因的影响知之甚少，尤其是淡水生态系统中的抗生素抗性基因（ARGs）和有机修复基因（ORGs）。在本研究中，我们利用GeoChip 5.0分析了青藏高原东部四姑娘山两个高海拔湖泊（HAL）和两个低海拔湖泊（LAL）之间的五类功能基因，包括ARGs、金属抗性基因（MRGs）、ORGs、噬菌体和毒力基因。HALs和LAL的基因丰富度（包括ARGs、MRGs、ORGs、噬菌体和毒力基因）没有发现差异（Student t检验，p>0.05）。HAL中大多数ARG和ORG的丰度高于LAL。对于MRGs，而铝在HAL中的含量高于LAL（Student’s t检验，p<0.05；所有Cohen’s d>0.8）。HAL中铅和汞的一些重金属抗性基因的丰度低于LAL（学生t检验，p<0.05；所有Cohn’s d<-0.8）。HALs中这些功能基因的组成与LAL显著不同。HAL中的功能基因网络也比LAL中的更复杂。我们推测，HALs中ARGs和ORGs的富集与不同的微生物群落、外源性ARGs以及由印度季风驱动的长期大气传输富集的持久性有机污染物有关。这项研究强调了高海拔偏远湖泊中ARGs、MRGs和ORGs的意外富集。
Abstract
Elevation has a strong effect on aquatic microbiome. However, we know little about the effects of elevation on functional genes, especially antibiotic resistance genes (ARGs) and organic remediation genes (ORGs) in freshwater ecosystems. In this study, we analyzed five classes of functional genes including ARGs, metal resistance genes (MRGs), ORGs, bacteriophages, and virulence genes between two high-altitude lakes (HALs) and two low-altitude lakes (LALs) in Mountain Siguniang at Eastern Tibetan Plateau by means of GeoChip 5.0. No differences (Student's t-test, p > 0.05) of gene richness including ARGs, MRGs, ORGs, bacteriophages, and virulence genes in HALs and LALs were found. The abundance of most ARGs and ORGs was higher in HALs than in LALs. For MRGs, the abundance of macro metal resistance genes of potassium, calcium, and aluminum was higher in HALs than in LALs (Student's t-test, p < 0.05; all Cohen's d > 0.8). The abundance of some heavy metal resistance genes of lead and mercury was lower in HALs than in LALs (Student's t-test, p < 0.05; all Cohen's d < −0.8). The composition of these functional genes in HALs differed significantly from in LALs. The functional gene network in HALs was also more complex than that in LALs. We speculate that enrichment of ARGs and ORGs in HALs is related to different microbial communities, exogenous ARGs, and enriched persistent organic pollutants through long-range atmospheric transport driven by the Indian monsoon. This study highlights the unexpected enrichment of ARGs, MRGs, and ORGs in remote lakes at high elevations.

https://www.sciencedirect.com/science/article/abs/pii/S0048969723011701